IBM ILOG CPLEX Optimization Studio Reviews

Modeling, solving the models, things like this.

It performs really well. I have experienced some trouble in the input data, but that's probably my fault more than CPLEX's fault.

It is good at solving models and it offers a lot of different solution methodologies that are already built-in, so it is pretty fast.

The overall benefit is that it makes it easy to validate models.

It might already have it, but in the next release I would like to be able to use other languages, like Python or C, in calling CPLEX to solve the model. I think this would make it easier for the input data.

It is pretty stable. I have never had any crashes.

If there is a lot of data, I have a hard time solving it with CPLEX.

My advisor told me that I needed to use CPLEX. I wasn't using a different solution beforehand.

The setup was easy.

We also use Gurobi, which is CPLEX's competitor. One reason why I use Gurobi more is because I use Python and it is easy to call Gurobi in Python.

If I were to advise someone who was looking to implement CPLEX I would say that they should learn about the input data and how to call it from other languages. OPL is the language that CPLEX uses, I think. I had a hard time using that.

I try to use CPLEX for the supply chain optimization problem.

I think that the most valuable feature is the integer program. It is powerful. 

I haven’t used CPLEX for many years and I just recently used it again. I needed to familiarize myself with it again, refresh my knowledge of the interface and the new system. I like the new system better. It is more convenient and has a good interface.

I like that it is fast, though this depends on different problems. To my knowledge, it is valuable for the integer and mixed-integer linear. Not for nonlinear, though. For nonlinear I would recommend other tools.

I would like see a more user-friendly interface, especially for new students. I would also like to have more options to choose from. Different problems have different options. We already have a different option in a CPLEX setting for the different search direction but I expect that we can combine with some heuristic matter, have that together.

For example, we might solve some stage at the beginning, find some infeasible and look at the bound. Then I can go to the feasible bound heuristic to find a good solution quickly.

The instillation of the software was straightforward.

It is pretty stable. It has not crashed this time, though this did happen with the older version when I worked on a large problem.

I have not recently used CPLEX for large-scale problems, but about five years ago I used it for a very large-scale problem. That problem was too complex. When I would read it and do the solving, I could not get the feasible solution for the long period. 

Before CPLEX I used to use GAMS and I still use both of them. GAMS has different links with different solvers. The solvers are developed by different companies but the functions are different. So the solver that I will choose to use depends on the problem.

CPLEX is a professional and very capable tool for large-scale integer and mixed integer, even linear.

I always recommend this software to my students, both undergraduate and grad students.

I need to do searches, solve mathematical modeling and obtain exact solutions, so I need to use CPLEX to obtain the exact solutions. I usually use CPLEX, but sometimes I use metaheuristics, and I use CPLEX to compare with metaheuristics. It is very convenient and very easy for me. 

It performs very well but because I'm not very familiar with it I still need to learn more about it.

It is easy to use compared to other software, like Lingo.

I would like for them to offer a free version. We have to use the version that we got from my teacher but sometimes it doesn't work. 

I would also like for there to be more tutorials explaining how to improve solutions. Sometimes I do not know how to improve my solution, so I need a tutorial for that.

Mostly it is good but sometimes it is very slow. My program, my problem, is a little bigger and my scale is a little larger.

I have not needed to use technical support. I got CPLEX from my teacher and if I have any problems I go to him for help.

I would certainly recommend CPLEX to my colleagues or friends at the university who are doing algorithms. I actually did advise my colleague to use it, because he is also doing the integer program.

I use CPLEX for network optimization, and the defaults don't work as well, but fortunately they have the callbacks that allow you to add your own additional nuances to the solver, and then that performs really well. 

The ability to actually incorporate some stuff that you have developed within CPLEX's big general framework. 

It is a very good tool. It's very user-friendly with its language, OPL. It can be used by someone who has no idea how to code, while also being very useful for someone who is very advanced in programming and has a lot of knowledge of the matter, of the material. So, I think it is very versatile for a very wide audience.

One of the new things in CPLEX is the new benders, the composition that does it automatically. One of the things I realized while testing it is that when it does it at the root node of the branch and bound tree, it doesn't leave with the LP relaxation. It often stops, terminates, before it stops adding cuts before. And it makes for a very weak stopping criteria later on in the branch and cut tree. So maybe polish it a little more. I know it is a very generic framework, but I think just by doing that one thing, it could really improve its performance for a lot of stuff. 

The stability is okay. For now, I haven't seen it crash. I have seen it become numerically unstable. One of the nice things about CPLEX is that it lets you know that there are certain numerical instabilities. I think that the new feature that they released in the 12.7 version manages to identify that these things are pernicious before trying to solve them, and it recommends other ways to correct that. 

The scalability really depends on the type of problems. For my particular types of problems, it's not as scalable because there are a large number of constraints to the problems. So, if I increase the number of variables, I significantly increase the number of constraints. For my particular problem, it's not as scalable. But that is the reason why I use these nuances for my problems.

I was not using any solutions previously. I ended up working on CPLEX because my adviser told me to.

It was very straightforward.

I would recommend to anyone who is looking to implement CPLEX that they read the documentation. I do not think that it is available on PDF, it is all on HTML now, but they can find the PDF file for the 12.5 version. I find it more friendly for navigation, so I'd tell them to read that one, and then for the particular things that are in the newest versions, they can go online.

I used CPLEX for optimization while working on my PhD thesis, as well as for writing papers. As to how it performed, sometimes CPLEX solved the cases better than me and sometimes I solved the cases better than CPLEX.

It is easy to use and has very large application areas for optimization problems for networks in teacher optimizations. There is also a lot of documentation available online, which is very helpful when I'm searching for information on how to do something in CPLEX. There is a very large community of people that use CPLEX.

I consider CPLEX to be a state-of-the-art tool and I can't compare the power of my algorithms with CPLEX and the impact that it has had on my PhD thesis.

Actually, when CPLEX adds something it becomes more difficult for me to publish a paper. Maybe CPLEX can sleep a little bit and not make any improvements for a while.

It is stable, though, in one case I noticed that the dual values of the decision variables were not in the correct order. But I managed to find the correct way of presenting that situation and I selected it.

I did write to IBM once about an issue related to cogeneration. They responded very quickly and were able to help me.

No, I didn't try any other programs but I heard about them from my friends who are using these kind of optimization programs.

When choosing to use CPLEX it was important to me that there were a lot of other people who were also using it and knew about it, which is how I knew that it is a good program. 

I would certainly recommend CPLEX to a friend or a colleague.

I've used it for optimization of linear models and, from what I've seen, it varies the speed compared to other libraries. 

The Speed. When you do large problems, that's when you see that it's fast. With other tools, solving large problems can take way longer. It is better to have the resource faster. 

There are also many APIs to connect to it.

I would like to see something more for problems that are not linear. That is what I am looking for. Conic problems, and stuff like that. Though maybe CPLEX has it already and I haven't seen it.

From what I've experienced, it doesn't crash that much. There have been a few crashes but compared to the other tools, it is better. 

I haven't used the technical support.

When I scaled the problem and it didn't solve as soon as I did it, it was taking too long, people told me, "Try CPLEX."

When it comes to choosing a vendor I look for people who have had a similar problem as me and I ask them how they solved it. If they tell me CPLEX then I go to CPLEX, and if they tell me something else then I go there.

I have only used CPLEX for a few specific cases so I feel it would be unfair to evaluate it without really seeings all of the things that it is capable of doing. But I would recommend it to others who are considering implementing CPLEX. There is a lot of material online of people solving problems with CPLEX, which is also super helpful.

Optimization, mathematical modeling. It's been quite satisfactory so far. It's my choice application.

What I like most about CPLEX that it can be called or it can work with many other applications. You can use it with AMPL, which is an application that I use frequently. You can call it, as far as I know from C++ or C#, which I did in the past. Then there's the OPLs suite that you can also use. What I like the most about it is you can actually have access to CPLEX through different interfaces.

And the fact that it can effectively solve integer models, which, most of the time, that's what we deal with.

It would be great if it also could handle nonlinear models or non-linearity. That would be a great complement to the software.

I haven't had any negative experience with stability.

I think that is okay, too. I don't have any complaints about that.

I haven't used it.

In terms of solvers, yes. For example, for nonlinear, I used different software like Baron, Gurobi, and the like. But for integer programs, I've always been using CPLEX.

I was involved in the procurement of it, but not the installation.

If they're working on integer programming, mathematical, they're probably already aware of CPLEX. I can't imagine that someone is working on an integer program and has not heard about CPLEX.

It's pretty much a standard, but if I come across someone who has never heard of it or is not experienced with it, then obviously I would recommend it to them, to give it a shot.

We are modeling different problems such radiation therapy optimization using CPLEX.

It is great, actually. It is great for small to medium size problems. When it goes to larger problems it is slow, but it is still understandable, it is still manageable.

Simplicity, and it's very comprehensive, a lot of information is there. And because many people are using it you can find almost whatever your question is online.

Another feature that I like is that you can do a lot of constraint programming, which is a unique feature in CPLEX, you cannot do this almost anywhere else.

I think one important feature to improve would be the speed of solving the problems. I know that CPLEX and other companies are trying to build new models, a new solution base to enhance the speed of solving problems. I think that is important. 

Also, it would be helpful if you had a more straightforward base to connect CPLEX to other software - to Java, to Python, and others. Make a platform so that it can be connected it to simulation software. That would be a plus.

It is fine.

No issues.

I haven't used it.

When the problem is too large we use Gurobi at the same time. There are ways to connect these things. It's a little hard but it's still possible. So, Gurobi as a solver sometimes. 

I used AMPL but I feel that CPLEX is much bigger, much more professional and easier to use.

I was also using another software called Lindo, but that couldn't handle any big problems. I ended up searching for better solutions and I realized that our university has CPLEX, so I started using CPLEX and that was a life changing.

The constraint programming feature in CPLEX was something that pushed me as well. One of the problems I was solving should have been modeled as a constraint program model.

Straightforward.

Regarding advice to a colleague who is considering using CPLEX, I would say look into a very simple example. And there are handbooks available to guide you in CPLEX. Start to go through them and you can see how you can model it very easily, and you can get used to it, and then make more complex models.

I use it primarily for my research. My research involves a lot of solving, a lot of integer programs and linear programs, and I primarily use CPLEX for doing that.

It has been very good for me. It has helped me a lot in my research.

I think the speed, compared to other competitive software, is one of the things that I really like about CPLEX.

It also provides a very easy to use interface.

There is not much coding overhead to solve multi-dimensional problems. It allows me to just focus on the actual problem and not coding.

I'm pretty happy with the current release because I don't use a lot of fancy features of CPLEX. I use it just if I have to solve a linear program or I have to solve an integer problem.

There are some very rare cases when some integer programming problems are performed better by Gurobi compared to CPLEX, but it happens very rarely.

I have not faced any issues with instability in CPLEX. My problem-size is not that big. I'm not trying to explain super large problems.

I haven't used it.

Yes, I switched between Gurobi and CPLEX for a while there.

I wasn't involved.

I would strongly recommend using CPLEX as a problem solver. As I said earlier, in some cases - and I've heard this from some of my colleagues who have faced this problem - in somewhat large integer programming problems, Gurobi performs better in respects, but for me my problem size is not that big. For me they're both competitive to each other.